TWI530856B - Capacitive sensor device and capacitive sensor method - Google Patents

Description

Capacitive sensing device and method thereof

The present invention relates to a capacitive sensing technology, and more particularly to a capacitive sensing device capable of reducing the effects of transient environments and a background noise updating method thereof.

In order to improve the convenience of use, more and more electronic devices use a touch screen as an operation interface, so that the user can directly operate the screen on the touch screen to provide more convenient operation. User-friendly mode of operation. The touch screen is mainly composed of a display providing a display function and a sensing device providing a touch function.

The sensing device can be distinguished according to different configurations and sensing forms: a resistive sensing device, a capacitive sensing device, an acoustic wave sensing device, an optical (infrared) sensing device, and an electromagnetic sensing device. Among them, the capacitive sensing device does not require stress-strained material deformation, is less affected by ambient light, and the process is relatively simple. Therefore, most recent touch screens use capacitive sensing devices.

The capacitive sensing device has a matrix sensing node defined by an X electrode and a Y electrode. When the user operates the capacitive sensing device, the capacitance of the corresponding sensing node changes according to the user's operation, so that the capacitive sensing device determines the occurrence of the touch action. However, when the environment in which the capacitive sensing device is used varies greatly (for example, when the temperature changes greatly), The capacitance value of the capacitive sensing device rises or falls with temperature, so that the capacitive sensing device is mistakenly determined as a touch action. Therefore, how to effectively detect changes in capacitance to improve the performance of capacitive sensing devices is one of the directions that the industry is constantly striving for.

In an embodiment, a background noise update method of a capacitive sensing device includes: detecting a current measurement value of a plurality of reference points in a plurality of sensing points, and determining a current measurement value and current usage according to the reference points. The reference measurement value generates a current difference value, compares the current difference value with a change threshold value, detects a current measurement value of the complex sense point, and according to the current measurement value of the sensing points and the currently used reference The measured values produce a complex position signal for the sense points and an output of the position signal based on the reference signal. Wherein, when the current difference value is greater than the change threshold, a background noise update procedure is performed according to the current difference value to update the reference measurement value set to be currently used. The sensing points are defined by a plurality of interdigitated electrodes and configured as a matrix, and the reference points are located at the edges of the matrix. The sensing points are respectively set to the plurality of reference measurement values currently used.

In one embodiment, a capacitive sensing device includes: a storage unit, a signal sensor, a driving/detecting unit, a position detecting unit, and a control unit. The storage unit stores a complex array reference value corresponding to different current difference values and a reference signal, and one of the group reference measurement values is set to be currently used. The signal sensor includes: a plurality of first electrodes and a plurality of second electrodes. The first electrode is interleaved with the second electrode, and the first electrode and the second electrode define a plurality of sensing points arranged in a matrix. The complex reference measurements in each set of reference measurements correspond to the sense points, respectively. The driving/detecting unit is connected to the first electrode and the second electrode, and is configured to detect a current measurement value of the sensing point. Position detection unit And driving the detecting/detecting unit and the storing unit, and generating a current difference value according to the current measured value of the plurality of reference points and the currently used reference measuring value, according to the current measured value of the sensing point and the current use A set of reference measurements produces a complex position signal and controls the output of the position signal based on the reference signal. Among them, the reference point is located at the edge of the matrix. The control unit is connected to the storage unit, the driving/detecting unit and the position detecting unit, and is used for comparing the current difference value with a change threshold. Wherein, when the current difference value is greater than the change threshold, the control unit performs a background noise update procedure according to the current difference value to update the reference measurement value set to be currently used.

In summary, the capacitive sensing device and the background noise updating method thereof according to the present invention determine the timing of updating the background noise (ie, the reference measurement value) by the periodic inspection of the selected reference point, thereby quickly obtaining the temperature change. The degree of influence corresponds to the sensing reference of the position signal to ensure the correctness of the signal reading and enhance the reaction speed to the temperature change.

20‧‧‧ display

30‧‧‧Host

12‧‧‧ Controller

122‧‧‧Drive/Detection Unit

124‧‧‧A position detection unit

126‧‧‧ storage unit

128‧‧‧Control unit

14‧‧‧Signal Sensor

142‧‧‧First sensing layer

144‧‧‧Second sensing layer

A1‧‧‧Sensing area

A2‧‧‧ Invalid area

X1‧‧‧ first electrode

X2‧‧‧ first electrode

X3‧‧‧first electrode

Xn-2‧‧‧ first electrode

Xn-1‧‧‧first electrode

Xn‧‧‧first electrode

Y1‧‧‧second electrode

Y2‧‧‧ second electrode

Y3‧‧‧ second electrode

Ym-2‧‧‧second electrode

Ym-1‧‧‧second electrode

Ym‧‧‧second electrode

P(1,1)‧‧‧ Sensing point

P(1,m)‧‧‧ Sensing point

P(n,1)‧‧‧ Sensing points

P(n,m)‧‧‧ Sensing points

S11‧‧‧Detecting current measurements of multiple reference points

S13‧‧‧ generates a current difference value based on the current measured value of the reference points and the at least one reference measured value

S15‧‧‧Actain a selected adjustment factor based on a relationship setting and the current difference value generated

S17‧‧‧Detecting current measurements of multiple sensing points

S19‧‧‧ generates the position signals of the sensing points based on the current measured values of the sensing points

S21‧‧‧ Adjust these position signals according to the selected adjustment factor

S23‧‧‧Control the output of the adjusted position signal according to the reference signal

The current difference value and the first change threshold generated by S31‧‧‧ comparison

S33‧‧ Is the current difference value greater than the first change threshold?

S35‧‧‧ Increase the detection frequency of the current measurement value of the reference point

S37‧‧‧ count value plus 1

Does the S39‧‧‧ count value reach the established value?

S41‧‧‧Reducing the detection frequency of the current measured value of the reference point

S43‧‧‧ count value is zero

S45‧‧‧Do not adjust the detection frequency of the current measurement value of the reference point

S51‧‧‧ Take multiple capacitive sensing devices of the same specification manufactured at the same time

S53‧‧‧Measure the first measurement value of the same reference point and the reference point of each reference point of each capacitive sensing device in the non-touch state with the same sensing technology at the first temperature without interference source One position signal

S55‧‧‧Using statistical methods to calculate reference measurements from the first measured values

S57‧‧‧measing the second measurement value of each reference point of each capacitive sensing device in the non-touch state and each reference point by the same sensing technology at the second temperature without interference source Second position signal

S59‧‧‧ Statistical analysis using measurement results to obtain the correspondence between signal difference values and adjustment factors

S61‧‧‧ The reference measurement values obtained and their corresponding relationship settings are stored in the storage unit of each capacitive sensing device of the same specification.

S71‧‧‧ driving at least one electrode on the first side of the matrix and at least one electrode on the second side of the matrix

S73‧‧‧ Measure at least one electrode on the third side of the matrix and at least one electrode on the fourth side of the matrix to obtain the current measurement value of each reference point

S75‧‧‧ drive at least one electrode on at least one side of the matrix

S77‧‧‧ Measure at least one electrode on at least one side of the matrix to obtain current measurements of multiple reference points

S79‧‧‧ drive at least one first electrode on the first side (and the second side) of the matrix

S81‧‧‧Measure multiple second electrodes to get the current measurement of multiple reference points

S83‧‧‧ drive at least one second electrode on the third side (and fourth side) of the matrix

S85‧‧‧Measure multiple first electrodes to obtain current measurements of multiple reference points

The current difference value and the second change threshold generated by S91‧‧‧ comparison

S93‧‧ Is the current difference value greater than the second change threshold?

S95‧‧‧Perform background noise update procedure based on current difference values

S951‧‧‧Reading a set of reference measurement values corresponding to the current difference value from the storage unit and their corresponding relationship settings

S953‧‧‧Renewing the currently used reference measurement value by reading one of the group reference measurement values, and updating the current usage relationship setting by reading the relationship setting

[Fig. 1] is a block diagram showing a capacitive sensing device according to an embodiment of the present invention.

[Fig. 2] is a schematic plan view of the signal sensor.

[Fig. 3] is a flowchart of a background noise updating method of a capacitive sensing device according to an embodiment of the present invention.

[Fig. 4] is a flowchart of a background noise updating method of a capacitive sensing device according to another embodiment of the present invention.

[Fig. 5] is a flowchart of a method of establishing a relationship setting according to an embodiment of the present invention.

[Fig. 6] is a flow chart showing the measuring step of the measured value of the reference point of an embodiment.

[Fig. 7] is a flow chart showing the measurement step of the measurement value of the reference point of another embodiment.

[Fig. 8] is a flow chart showing the measurement step of the measurement value of the reference point of still another embodiment.

[Fig. 9] is a flowchart of a background noise updating method of a capacitive sensing device according to still another embodiment of the present invention.

[Fig. 10] is a detailed flowchart of an embodiment of the step S95.

1 is a block diagram of a capacitive sensing device in accordance with an embodiment of the present invention. Referring to FIG. 1 , the touch screen includes a capacitive sensing device, a display 20 , and a host 30 . The capacitive sensing device includes a controller 12 and a signal sensor 14. The signal sensor 14 is connected to the controller 12, and the signal sensor 14 is located on the display surface of the display 20. The signal sensor 14 includes a plurality of electrodes (for example, first electrodes X1, X2 to Xn-1, Xn and second electrodes Y1, Y2 to Ym-1, Ym) arranged in a staggered manner. Where n and m are positive integers. n can be equal to m or not equal to m.

In some embodiments, the first electrodes X1, X2~Xn-1, Xn and the second electrodes Y1, Y2~Ym-1, Ym may be located in different planes. In other words, the signal sensor 14 includes a first sensing layer 142 and a second sensing layer 144. The second sensing layer 144 is located on the first sensing layer 142 and the first sensing layer 142 is located on the display surface of the display 20. The first sensing layer 142 and the second sensing layer 144 may be, but are not limited to, sandwiched with an insulating layer (not shown).

The first sensing layer 142 has a plurality of electrodes (ie, first electrodes X1, X2 to Xn-1, Xn) formed by patterning. The first electrodes X1, X2 to Xn-1, and Xn are arranged in parallel with each other. Similarly, the second sensing layer 144 also has a plurality of electrodes (ie, second electrodes Y1, Y2 to Ym-1, Ym) formed by patterning. From a top view, the first electrodes X1, X2~Xn-1, Xn and the second electrodes Y1, Y2~Ym-1, Ym are interdigitated and defined The complex sensing points P(1,1)~P(n,m) of a matrix configuration are as shown in Fig. 2. In other words, the first electrodes X1, X2 to Xn-1, Xn and the second electrodes Y1, Y2 to Ym-1, Ym constitute a planar coordinate system. Taking this implementation as an example, the first electrodes X1, X2~Xn-1, Xn and the second electrodes Y1, Y2~Ym-1, Ym form a right angle coordinate system (Cartesian Coordinate System). However, the invention is not limited thereto, and may be a polar coordinate system, a non-orthogonal coordinate system, or other planar coordinate system. In some embodiments, the top views of the overlapped first electrodes X1, X2~Xn-1, Xn and the second electrodes Y1, Y2~Ym-1, Ym have a diamond-shaped honeycomb shape, a grid shape or a grid shape.

In addition, in some embodiments, the first electrodes X1, X2~Xn-1, Xn and the second electrodes Y1, Y2~Ym-1, Ym may be located in the same plane, that is, only on a single sensing layer.

Herein, the sensing layer (eg, the first sensing layer 142 and the second sensing layer 144) may adopt a transparent or translucent design, so that when the display 20 displays information, the user can penetrate all the sensing layers. The content displayed on the display 20 is seen. In other words, light from display 20 can pass through all of the sensing layers to the user's eyes. In some embodiments, the sensing layer can be a patterned conductive film such as, but not limited to, an indium oxide (ITO) tin film.

In general, the area in which the display 20 is used to display information is referred to as an active area, and the area in which the signal sensor 14 overlaps the active area may be referred to as a sensing area A1. The signal sensor 14 is capable of detecting a touch event occurring on the sensing area A1. Herein, the term "touch event" means an actual touch (ie, a finger or object directly contacts the signal sensor 14) or an almost touch (ie, a finger or object is in close proximity but does not directly contact the signal sensor) 14). In some embodiments, all of the sensing points P(1,1)~P(n,m) of the signal sensor 14 are all on the active area, ie, do not have Invalid area A2. In some embodiments, the partial sensing points P(1,1)~P(1,m), P(n,1)~P(n,m) of the signal sensor 14 are not located on the active area. In other words, the signal sensor 14 has an inactive area A2, and the inactive area A2 is located at the edge of the sensing area A1. The signal sensor 14 does not detect a touch event occurring on the invalid area A2.

When the touch screen operates, the host computer 30 transmits the information to be displayed to the display 20 of the touch screen, and the display 20 displays a screen having information to be displayed. When the user touches the specific position of the capacitive sensing device that overlaps the display 20 according to the screen displayed on the display 20, the capacitive sensing device outputs a corresponding position signal to the host 30 in response to the touch event to be performed by the host 30. Further processing. Herein, the content of the "further processing" depends on the execution instruction assigned to the position where the display 20 is touched, for example, but not limited to, the host 3 activates an application in response to the position signal, or is in the position where the display 20 is touched. Show strokes and more. In other words, host 30 receives a position signal from a self-capacitive sensing device and is configured to initiate an action based on the position signal.

The controller 12 includes a driving/detecting unit 122, a position detecting unit 124, a storage unit 126, and a control unit 128. The driving/detecting unit 122 includes a driving component and a detecting component. The driving component and the detecting component can be integrated into a single component or two components, which are determined by the current state of the design. The driving/detecting unit 122 is coupled to the first electrodes X1, X2 XXn-1, Xn and the second electrodes Y1, Y2~Ym-1, Ym. The position detecting unit 124 is coupled to the driving/detecting unit 122, the storage unit 126, and the host 30. The control unit 128 is coupled to the driving/detecting unit 122 and the position detecting unit 124. Here, the control unit 128 is used to control the operation of the driving/detecting unit 122.

The controller 12 drives/detects the unit 122 when sensing the touch situation of the user. Self-capacitance sensing technology can also be used, and self-capacitance sensing technology can also be used to detect the measured values of the sensing points. Here, the measured value may be a signal such as voltage, current, charge/discharge time, and the like. In other words, the driving/detecting unit 122 detects the current measurement value of each sensing point, and the position detecting unit 124 knows the electrical power of each sensing point according to the detected current measurement value and the corresponding reference quantity measurement value. Capacity or capacitance change (ie, position signal).

Here, the sensing point of the specific position is set as the reference point, in particular, the sensing point located in the invalid area A2 or the sensing point where the bit is less likely to occur in the sensing area A1. In other words, the sensing points located at the edges of the matrix among the sensing points P(1, 1) to P(n, m) are set as reference points.

In the normal working cycle, the control unit 128 controls the driving/detecting unit 122 to cause the driving/detecting unit 122 to perform the signal detecting action of the reference point at a specific detection frequency. Here, the specific detection frequency may be performed, for example, but not limited to, every 2 to 5 seconds.

Referring to FIG. 3, the control unit 128 controls the driving/detecting unit 122 to cause the driving/detecting unit 122 to detect the current measurement value of the reference point (step S11). The position detecting unit 124 generates a current difference value according to the current measured value of the reference point and the at least one reference measured value (step S13). Next, the position detecting unit 124 obtains an selected adjustment factor according to a relationship setting and the generated current difference value (step S15). Here, the relationship is set to the correspondence between the signal difference value and the adjustment factor of the respective different temperatures.

Then, the control unit 128 controls the driving/detecting unit 122 to cause the driving/detecting unit 122 to detect the current measurement values of all the sensing points located in the sensing area A1 (step S17). The position detecting unit 124 generates the sensing points according to the current measured values of the sensing points. A plurality of position signals (step S19). In other words, the driving/detecting unit 122 calculates the current difference value (capacity or capacitance change) of each sensing point according to the current measured value of each sensing point and the corresponding reference quantity measured value, as the sensing points. Position signal. Next, the position detecting unit 124 adjusts the generated position signal according to the selected adjustment factor (step S21), and controls the output of the adjusted position signal based on the reference signal (step S23).

In some embodiments, referring to FIG. 4, after each time the current difference value is obtained (step S13), the control unit 128 compares the generated current difference value with a change threshold (hereinafter referred to as a first change threshold) (step S31). ). When the generated current difference value is greater than the first change threshold (step S33), the control unit 128 increases the detection frequency of the signal detecting action of the reference point by the driving/detecting unit 122 (step S35).

In some embodiments, when the generated current difference value is not greater than the first change threshold (step S33), the control unit 128 controls the counter to increment the count value by 1 (step S37), and determines whether the count value reaches a predetermined value ( Step S39). When the count value reaches a predetermined value, the control unit 128 reduces the detection frequency of the signal detecting action of the reference point by the driving/detecting unit 122 (step S41).

And, upon or after determining that the detection frequency is to be adjusted (step S41 or step S35), the control unit 128 resets the counter to zero the count value (step S43).

On the other hand, when the count value does not reach the predetermined value, the control unit 128 does not adjust the detection frequency (step S45).

In some embodiments, relationship settings can be established in the following manner.

Referring to Figure 5, a plurality of capacitive sensing devices (eg, 10, 20, 30 or more) of the same specifications (eg, the same size and the same glass thickness) are simultaneously manufactured. (Step S51).

Measuring one or more of each capacitive sensing device with the same sensing technique at a first temperature without interference source (eg, temperature control at 26 ° C, 27 ° C or 28 ° C) The measured values of the same reference point in the no-touch state (referred to as the first measured value) and the position signals of the respective sensing points (referred to as the first position signal) (step S53).

The reference measurement value is calculated by using the statistical method to measure the first measurement value (step S55).

In one embodiment, the first measurement values of the reference points of the same position of each capacitive sensing device are averaged to obtain reference measurement values corresponding to the reference points. In this case, the first measurement value deviation of the reference point of the same position of each capacitive sensing device may be deleted first, and then averaged. At this time, in step 13, the current measurement value of each reference point is used to calculate the individual difference value by the corresponding reference quantity measurement, and then the statistical analysis of all the individual difference values is performed to obtain the current difference value.

In another embodiment, the first measurement values of all reference points of each capacitive sensing device are averaged to obtain a reference measurement value shared by each reference point. In this case, the first deviation of the first measurement values of all the reference points may be deleted first, and then averaged. At this time, in step 13, the current measured values of each reference point are calculated by the same reference quantity, and then the statistical analysis of all the individual difference values is performed to obtain the current difference value.

In another embodiment, the first measurements of all reference points of the capacitive sensing devices located on the electrodes at the same relative position are averaged to obtain a reference amount shared by the reference points on the electrodes at the relative positions. Measured value. In this case, the first deviation of all the reference points of the reference points on the electrodes at the same relative position may be deleted first, and then averaged. At this time, in step 13, the current measurement value of each reference point is used to calculate the individual difference value by the corresponding reference quantity measurement, and then the statistical analysis of all the individual difference values is performed to obtain the current difference value.

The method for deleting the larger deviation is, for example, but not limited to, deleting the largest one, or the smallest one, or the largest one and the smallest one, or the difference from the intermediate value exceeding a predetermined value. The statistical analysis of all individual difference values also includes the deletion of the larger of all individual difference values.

Measuring, under the same number of times of the same sensing technology, each capacitive sensing device is in a non-touch state under a plurality of second temperatures (eg, greater than or less than the first temperature) of the interference source within a range of operating temperatures The measured values of the same reference point (referred to as second measured values) and the position signals of the respective sensing points (referred to as second position signals) (step S57).

Performing statistical analysis using the measurement result (the first measurement value at the first temperature and the corresponding first position signal and the second measurement value at the second temperature and the corresponding second position signal) to obtain a corresponding difference The signal difference value of the temperature (representing the temperature change between the first temperature and the second temperature) and the adjustment factor (representing the signal change between the first position signal and the second position signal corresponding to each temperature change) The relationship of the correspondence relationship is set (step S59). Here, the relationship setting may be a correspondence table of signal difference values and adjustment factors of different temperatures, or a variation curve of signal difference values with respect to adjustment factors of corresponding different temperatures, or signal difference values and adjustment factors of corresponding different temperatures. Conversion relationship. In an embodiment of step S15, the position detecting unit 124 finds a signal difference value that matches the current difference value in the relationship setting, and obtains an adjustment factor corresponding to the signal difference value that matches the current difference value (ie, the selected adjustment factor). ). In another embodiment of step S15, the position detecting unit 124 takes the current difference value into the relationship setting to be converted into a corresponding adjustment factor (ie, Selected adjustment factor).

Here, the first temperature differs from any adjacent two temperatures of the plurality of second temperatures by at least one scale (for example, 1 ° C, 2 ° C, 5 ° C or 10 ° C). When the scale of the phase difference is small, the signal difference values corresponding to the plurality of temperatures may be the same value, and a plurality of different signal difference values may also correspond to the adjustment factors of the same value.

The relationship between the obtained reference measurement value and the corresponding relationship is stored in the storage unit 128 of each capacitive sensing device of the same specification (step S61) for use in performing step S13 and step S15.

In some embodiments, the reference points may be located on k electrodes X1~Xk, Xn-k-1~Xn, Y1~Yk, Ym-k-1~Ym (hereinafter referred to as reference electrodes) at respective edges of the matrix. Where k is a positive integer less than n and m. Preferably, k is a positive integer less than n/10 and m/10. More preferably, k is 1 or 2. Here, the reference point may be one, more or all of the sensing points on each of the reference electrodes.

In addition, one or more sensing points of non-reference points are spaced between any two reference points on the same reference electrode. Furthermore, there are the same number of non-reference point sensing points between any two reference points on the same electrode.

In some embodiments, the reference point is a sensing point that is located at four corners of the matrix, ie, the reference point is a*b sensing points at each corner of the matrix. Here, a is a positive integer smaller than n; preferably, a is a positive integer smaller than n/10; more preferably, a is 1 or 2. Further, b is a positive integer smaller than m; preferably, b is a positive integer smaller than m/10; more preferably, b is 1 or 2.

In some embodiments, the reference point is a sensing point located in the inactive area, for example: sensing point P(1,1)~P(1,m), P(n,1)~P(n,m) One or more of them.

In some embodiments, when the touch screen is assembled with other devices (eg, host 30) into a single electronic device, the reference point can avoid the heat source of other devices. In other words, the sensing points in a given area above the heat source elements of other devices are not used as reference points.

Here, the reference points used in the measurement step of the first measurement value in step S11 and step S53 and the measurement step of the second measurement value in step S57 are the same.

For the measurement step of the first measurement value in step S11 and step S53 and the measurement step of the second measurement value in step S57, refer to the first, second and sixth figures. In the first embodiment, the reference point is 2*1 sensing points located in each corner (P(1,1), P(2,1), P(1,m), P(2,m), P(n,1),P( For example, n-1, 1), P(n, m), and P(n-1, m)), the driving/detecting unit 122 drives the two first electrodes X1 and X2 located on the first side of the matrix and The two first electrodes Xn-1, Xn are located on the second side of the matrix (step S71). Wherein the first side is opposite to the second side.

And the driving/detecting unit 122 measures a second electrode Y1 located on the third side of the matrix and a second electrode Ym located on the fourth side of the matrix, thereby obtaining the current measurement value of each reference point. (Step S73). Wherein the third side is opposite to the fourth side. The third side is connected between one end of the first side and one end of the second side, and the fourth side is connected between the other end of the first side and the other end of the second side.

In other words, in the second diagram, the driving/detecting unit 122 drives the two first electrodes X1 and X2 from the leftmost number of the signal sensor 14 and the second from the rightmost number of the signal sensor 14. One electrode Xn-1, Xn. The driving/detecting unit 122 measures a second electrode Ym located at the uppermost side of the signal sensor 14 and a second electrode Y1 located at the lowermost side of the signal sensor 14.

Steps and steps for measuring the first measurement value in step S11 and step S53 The measuring step of the second measured value in S57, in the second embodiment, if one reference point is used as a sensing point in each corner (P(1,1), P(1,m), P For example, (n, 1) and P(n, m)), the driving/detecting unit 122 drives a first electrode X1 located on the first side (leftmost) of the matrix and on the second side of the matrix. A first electrode Xn of the side (rightmost side) (step S71). Moreover, the driving/detecting unit 122 measures a second electrode Y1 located on the third side (lowermost side) of the matrix and a second electrode Ym located on the fourth side (uppermost side) of the matrix, thereby The current measurement value of each reference point is obtained (step S73).

For the measurement step of the first measurement value in step S11 and step S53 and the measurement step of the second measurement value in step S57, in the third embodiment, if the reference point is in the 1*2 of each corner Sensing points (P(1,1), P(1,2), P(1,m-1), P(1,m), P(n,1),P(n,2),P For example, (n, m-1) and P(n, m)), the driving/detecting unit 122 drives a first electrode X1 located on the first side of the matrix and a second side of the matrix. A first electrode Xn (step S71). And the driving/detecting unit 122 measures the second electrodes Y1 and Y2 located on the third side of the matrix and the second electrodes Ym-1 and Ym located on the fourth side of the matrix, thereby obtaining each reference. The current measured value of the point (step S73).

For the measurement step of the first measurement value in step S11 and step S53 and the measurement step of the second measurement value in step S57, refer to the first, second and seventh figures. In the fourth embodiment, the reference point is Taking the sensing point on an electrode on the first side of the matrix and the driving/detecting unit 122 taking the self-capacitance sensing technology as an example, the driving/detecting unit 122 drives the first bit on the first side of the matrix. An electrode X1 (step S75), and measuring a first electrode X1 located on the first side of the matrix to obtain a plurality of reference points (ie, sensing points P(1,1)~P(1,m) The current measured value of ))) (step S77). In this embodiment, the reference point (ie, the sensing point P(1,1)~P(1,m)) Also located in the invalid area A2.

For the measurement step of the first measurement value in step S11 and step S53 and the measurement step of the second measurement value in step S57, in the fifth embodiment, the reference point is located on the first side of the matrix. The sensing point on the two electrodes and the driving/detecting unit 122 adopts a self-capacitance sensing technology as an example. The driving/detecting unit 122 drives the two first electrodes X1 and X2 located on the first side of the matrix (step S75). And measuring the two first electrodes X1, X2 located on the first side of the matrix to obtain a plurality of reference points (ie, sensing points P (1, 1) ~ P (1, m), P (2 The current measured value of 1) to P(2, m)) (step S77).

For the measurement step of the first measurement value in step S11 and step S53 and the measurement step of the second measurement value in step S57, in the sixth embodiment, one of the sides of the matrix is referenced by the reference point. For example, the driving/detecting unit 122 drives and measures a first electrode X1 located on the first side of the matrix to obtain multiple The current measurement of the reference point (ie, the sensing point P(1,1)~P(1,m)). The driving/detecting unit 122 drives and measures a first electrode Xn located on the second side of the matrix to obtain a plurality of reference points (ie, sensing points P(n, 1)~P(n, m) The current measurement value. The driving/detecting unit 122 drives and measures a second electrode Y1 located on the third side of the matrix to obtain a plurality of reference points (ie, sensing points P(1, 1)~P(n, 1) The current measurement value. Moreover, the driving/detecting unit 122 drives and measures a second electrode Ym located on the fourth side of the matrix to obtain a plurality of reference points (ie, sensing points P(1, m)~P(n, Current measurement of m)). In this embodiment, a part of the reference points (ie, the sensing points P(1,1)~P(1,m) and P(n,1)~P(n,m)) are also located in the invalid area A2. Inside.

Steps and steps for measuring the first measurement value in step S11 and step S53 For the measurement step of the second measurement value in S57, referring to the first, second and eighth diagrams, in the seventh embodiment, the i reference bits are located on a first electrode X1 of the first side of the matrix. The sensing point and the driving/detecting unit 122 take the mutual capacitance sensing technology as an example, and i is an arbitrary integer of 1 to m. Preferably, i is less than m. More preferably, i is less than m/2. The driving/detecting unit 122 drives a first electrode X1 located on the first side of the matrix (step S79), and measures the i second electrodes to obtain current measurement values of the plurality of reference points (step S81). ). Here, the measured second electrodes are spaced apart from each other by one or a plurality of second electrodes. Furthermore, the i second electrodes can be spaced apart by the same number of unmeasured second electrodes or a different number of unmeasured second electrodes. Taking the difference as an example, if there are a total of 16 second electrodes, step S77 can measure the second electrodes Y1, Y5, Y9, and Y13 of the first, fifth, ninth, and thirteenth portions to obtain a plurality of reference points (ie, senses). The current measured values of the measuring points P(1,1), P(1,5), P(1,9), P(1,13)). Here, although a single electrode is driven as an example, the present invention is not limited thereto, and may be applied to a plurality of first electrodes driving the same side or a plurality of first electrodes driving different sides.

For the measurement step of the first measurement value in step S11 and step S53 and the measurement step of the second measurement value in step S57, in the eighth embodiment, the drive/detection unit 122 can drive the bit in the matrix. A first electrode Xn of the second side (step S79), and measuring the i second electrodes to obtain current measurement values of the plurality of reference points (step S81). Following the foregoing example, if the total number of the second electrodes is 16, the driving/detecting unit 122 can obtain a plurality of reference points (ie, sensing points P(1, 1), P(1, 5), P(1, 9), current measurement of P(1,13), P(n,1), P(n,5), P(n,9), P(n,13)).

For the step of measuring the first measurement value in step S11 and step S53 and the measurement step of the second measurement value in step S57, in the ninth embodiment, in step S81, driving / The detecting unit 122 first obtains the current measured value of a part of the reference point. Next, the driving/detecting unit 122 drives a second electrode Y1 located on the third side of the matrix (step S83), and measures the j first electrodes to obtain the current measurement value of the other partial reference point (step S85). Here, j is an arbitrary integer from 1 to n. Preferably, j is less than n. More preferably, j is less than n/2. And, the measured j first electrodes are spaced apart from each other by one or a plurality of first electrodes that are not subjected to measurement. Furthermore, the j first electrodes can be spaced apart by the same number of unmeasured first electrodes or a different number of unmeasured first electrodes. Following the foregoing example, if there are a total of 16 first electrodes, step S85 can measure the first, second, ninth, and thirteenth first electrodes X1, X5, X9, and X13 in an equal manner to obtain a plurality of reference points (ie, The current measured values of the sensing points P(1,1), P(5,1), P(9,1), P(13,1)). Herein, although driving a second electrode as an example, the present invention is not limited thereto, and can be similarly applied to driving a plurality of second electrodes on the same side or driving different sides (ie, the third side and the fourth side) a plurality of second electrodes on the side).

In the tenth embodiment, all of the reference points are located in the invalid area. Therefore, in the step of measuring the first measured value in steps S11 and S53 and the measuring step of the second measured value in step S57, the driving/detecting unit 122 drives or/and measures the first electrode. X1, Xn. In step S17, the driving/detecting unit 122 does not drive or/and measure the first electrodes X1, Xn.

Here, the driving/detecting unit 122 sequentially drives the electrodes one by one and sequentially measures the electrodes one by one. Furthermore, the driving/detecting unit 122 can simultaneously drive a plurality of electrodes in the same direction and simultaneously measure a plurality of electrodes in the same direction.

In some embodiments, the storage unit 126 stores a relationship setting between the complex array reference measurement value and each set of reference measurement values. Here, each set of reference measurements corresponds to A temperature (ie, corresponding to one or more signal difference values). In other words, these sets of reference measurements correspond to different temperatures.

Referring to Fig. 9, after each time the current difference value is obtained (step S13), the control unit 128 first compares the generated current difference value with a change threshold value (hereinafter referred to as a second change threshold value) (step S91). When the generated current difference value is greater than the second change threshold (step S93), the control unit 128 performs a background noise update procedure according to the current difference value (step S95) to update the currently used reference measurement value to the use environment. (eg, ambient temperature) one of the set of reference measurements and their corresponding relationship settings. Then, step S17, step S19, and step S23 are successively performed (step S21 is not performed). When the generated current difference value is not greater than the second change threshold (step S93), step S15 is continuously performed.

In an embodiment of step S95, referring to FIG. 10, the control unit 128 reads out, from the storage unit 126, a set of reference measurement values corresponding to the current difference value and their corresponding relationship settings (step S951). Then, the control unit 128 updates the reference measurement value currently used to perform the steps S13 and S19 by reading out one of the group reference measurement values (step S953). Then, the control unit 128 sets the update current setting to the relationship setting used when the step S15 is executed in the read relationship relationship (step S953).

In some embodiments, the signal detection action of the reference point can be directly applied to determine the timing of updating the background noise (ie, the reference measurement). In other words, when the generated current difference value is not greater than the second change threshold (step S93), step S15 is not performed, but step S17 is successively performed. In step S951, the read one set of reference measurement values respectively correspond to the complex sense points P(1, 1) to P(n, m). The set of reference measurements corresponding to different current difference values can be pre-established and stored in the storage unit 126. In other words, the storage unit 126 stores the pair The complex array reference value of the current difference value should be different, and the plurality of reference measurement values in each set of reference measurement values respectively correspond to the complex sensing points P(1, 1)~P(n, m). One of the group reference measurement values is set to be currently used as used when performing steps S13 and S19. The method for establishing a set of reference measurement values corresponding to different current difference values is well known in the art, and therefore will not be described again.

It should be understood that the order of execution of the steps is not limited to the foregoing described order, and the order of execution may be appropriately adapted depending on the execution content of the steps. Here, the storage unit 126 can be implemented by one or more storage elements. Each of the foregoing storage elements is used to store or temporarily store related software/firmware programs, data, signals, values, files, or a combination thereof. The storage element may be, for example, a volatile memory or a non-volatile memory, but is not limited thereto.

In summary, the capacitive sensing device and the background noise updating method thereof according to the present invention determine the timing of updating the background noise (ie, the reference measurement value) by the periodic inspection of the selected reference point, thereby quickly obtaining the temperature change. The degree of influence corresponds to the sensing reference of the position signal to ensure the correctness of the signal reading and enhance the reaction speed to the temperature change.

While the present invention has been described above in the foregoing embodiments, it is not intended to limit the invention, and the invention may be modified and modified without departing from the spirit and scope of the invention. The scope of patent protection shall be subject to the definition of the scope of the patent application attached to this specification.

S13‧‧‧ generates a current difference value based on the current measured value of the reference points and the at least one reference measured value

S15‧‧‧Actain a selected adjustment factor based on a relationship setting and the current difference value generated

S17‧‧‧Detecting current measurements of multiple sensing points

S19‧‧‧ generates the position signals of the sensing points based on the current measured values of the sensing points

S23‧‧‧Control the output of the adjusted position signal according to the reference signal

The current difference value and the second change threshold generated by S91‧‧‧ comparison

S93‧‧ Is the current difference value greater than the second change threshold?

S95‧‧‧Perform background noise update procedure based on current difference values

Claims (16)

A sensing method of a capacitive sensing device, comprising: detecting a current measurement value of a plurality of reference points in a plurality of sensing points, wherein the sensing points are defined by a plurality of interdigitated electrodes and configured as a matrix, The sensing points are respectively set to the currently used complex reference measurement values, and the reference points are located at the edge of the matrix; the current measurement values according to the reference points and the reference measurements currently used The value generates a current difference value; compares the current difference value with a change threshold; when the current difference value is greater than the change threshold, performing a background noise update procedure according to the current difference value to update the setting to be currently used The reference measurement values; detecting the plurality of current measurement values of the sensing points; generating the sensing points according to the current measurement values of the sensing points and the reference measurement values currently used a plurality of position signals; and controlling the output of the position signals based on a reference signal. The sensing method of claim 1, wherein the step of performing a background noise update procedure according to the current difference value comprises: reading a set of reference measurement values corresponding to the current difference value from a storage unit; The reference measurement values currently used are updated with the set of reference measurement values read out. The sensing method of claim 1, wherein the step of detecting a current measurement value of the plurality of reference points in the plurality of sensing points comprises: Driving at least one electrode of the electrodes at a first side of the matrix and at least one electrode positioned at a second side of the matrix, wherein the first side is opposite the second side; and measuring Having at least one electrode on the third side of the matrix and at least one electrode on the fourth side of the matrix to obtain the current measurements of the reference points, wherein the third side The side is opposite to the fourth side. The sensing method of claim 1, wherein the detecting the current measurement value of the plurality of reference points in the plurality of sensing points comprises: driving and measuring the middle of the electrodes on at least one side of the matrix At least one electrode to obtain the current measured values of the reference points. The sensing method of claim 1, wherein the electrodes comprise a plurality of first electrodes and a plurality of second electrodes interleaved with the first electrodes, and a current amount of the plurality of reference points in the detected complex sensing points The step of measuring includes driving at least one of the first electrodes in the first side of the matrix and at least one of the second sides of the matrix, wherein the first side is opposite to the first side a second side; and measuring a plurality of the second electrodes to obtain the current measurements of the reference points. The sensing method of claim 5, wherein at least one of the second electrodes that are measured is separated by at least one second electrode that is not measured. The sensing method of claim 1, wherein the electrodes comprise a plurality of first electrodes and a plurality of second electrodes interleaved with the first electrodes, and a current amount of the plurality of reference points in the detected complex sensing points The step of measuring includes driving at least one of the first electrodes in the first side of the matrix and at least one of the second sides of the matrix, wherein the first side is opposite to the first side a second side; measuring at least one of the second electrodes to obtain the current measured values of the plurality of the reference points; driving the second electrodes to be at a third side of the matrix At least one of the sides and at least one of the fourth sides of the matrix, wherein the third side is opposite the fourth side; and measuring at least one of the first electrodes to obtain the The current measurements of the remaining of the reference points. The sensing method of claim 7, wherein at least one of the first electrodes that are measured is separated by at least one first electrode and the second ones are measured At least one second electrode that is not measured is spaced between any of the electrodes. The sensing method of claim 1, wherein the matrix is divided into a sensing area and an invalid area located at an edge of the sensing area, and the reference points are located in the invalid area. The sensing method according to any one of claims 1 to 9, further comprising: comparing the current difference value with another change threshold; increasing the current difference value when the current difference value is greater than the another change threshold The detection frequency of the current measured values of the reference point. The sensing method according to any one of claims 1 to 9, further comprising: Comparing the current difference value with a change threshold; when the current difference value is greater than the change threshold, increasing the detection frequency of the current measurement values of the reference points and resetting a count value; when the current difference When the value is not greater than the change threshold, the count value is accumulated; when the count value reaches a predetermined value, the detection frequency of the current measurement values of the reference points is decreased and the count value is reset; When the count value does not reach the predetermined value, the detection frequency of the current measurement values of the reference points is not adjusted. A capacitive sensing device includes: a storage unit that stores a complex array reference value corresponding to different current difference values and a reference signal, wherein one of the group reference measurement values is set to be currently used; The sensor includes: a plurality of first electrodes and a plurality of second electrodes, wherein the first electrodes are interlaced with the second electrodes, and the first electrodes and the second electrodes define a complex sense in a matrix configuration a plurality of reference measurement values in each of the set of reference measurement values respectively corresponding to the sensing points; a driving/detecting unit connecting the first electrodes and the second electrodes for Detecting current measurement values of the sensing points; a position detecting unit connecting the driving/detecting unit and the storage unit for determining the current measurement according to the plurality of reference points in the sensing points And generating a current difference value from the currently used reference measurement values, generating a complex position signal according to the current measurement values of the sensing points and the currently used set of reference measurement values, and controlling according to the reference signal Some of these Counter output signal, wherein the plurality of reference point located on the edge of the matrix; and a control unit, the storage unit, the driving/detecting unit and the position detecting unit for comparing the current difference value with a change threshold, wherein when the current difference value is greater than the change threshold, the control The unit performs a background noise update procedure based on the current difference value to update the set of reference measurement values set to be currently used. The capacitive sensing device of claim 12, wherein in the background noise update program, the control unit reads the set of reference measurement values corresponding to the current difference value from the storage unit, and reads The set of reference measurements updates the reference measurements currently in use. The capacitive sensing device of claim 12, wherein the reference points are located at a corner of the matrix. The capacitive sensing device of claim 12, wherein the matrix is divided into a sensing region and an inactive region located at an edge of the sensing region, and the reference points are located in the inactive region. The capacitive sensing device according to any one of claims 12 to 15, wherein the control unit is further configured to adjust the driving/detecting unit to the reference points according to the current difference value and another change threshold. The detection frequency of the current measured values.